feat: Adding watsonx support in Haystack

[divyaruhil]

Related Issues

#link

Proposed Changes:

Add WatsonxGenerator and WatsonxChatGenerator components to wrap IBM watsonx.ai’s text- and chat-generation APIs (supporting streaming, custom models, and generation parameters).

Add WatsonxTextEmbedder and WatsonxDocumentEmbedder components that support embedding use cases for both text and documents.

Ensure all components follow the existing Haystack interfaces and patterns for Generator and Embedder.

Include tests files accordingly.

How did you test it?

• Created unit and integration test files for the new WatsonxGenerator, WatsonxTextEmbedder, and WatsonxDocumentEmbedder components.
• Verified functionality by running the test suite to ensure all components behave as expected.
• Manually tested by importing the components into a Jupyter Notebook and running example queries to confirm that:
  --Text generation works with WatsonxGenerator
  --Chat generation works with WatsonxChatGenerator
  -- Embeddings are correctly generated for both text and documents using the respective embedder components

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test: and added ! in case the PR includes breaking changes.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[CLAassistant]

All committers have signed the CLA.

[sjrl]

Hey @divyaruhil we appreciate your work on this, but take a look at my comment here deepset-ai/haystack-core-integrations#1891 (comment)

[divyaruhil]

Sure @sjrl , I'll go through the comment , Thankyou !

[divyaruhil]

Closing this one as i have opened a pr :- deepset-ai/haystack-core-integrations#1949